<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script type="text/javascript">
    function foo(info){
        console.log(info);
        return info;
    } 
    var ret = foo('hello')
    console.log(ret);
    </script>
</head>
<body>
    <div>
    <!-- //函数的名字是不区分大小写 -->
    <!-- //自定义函数 -->
    <?php
    function foo($info){
        return $info;
    }
     $ret = foo('hi tom');
     echo $ret;

    //系统函数
    // $arr = array(111,222,333);
    $arr = array('a'=>'111','b'=>'222','c'=>'333');
    $ret = json_encode($arr);
    echo $ret;


    
    ?>
    
    </div>
</body>
</html>